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Publication numberUS4190345 A
Publication typeGrant
Application numberUS 05/924,653
Publication dateFeb 26, 1980
Filing dateJul 14, 1978
Priority dateJul 14, 1978
Publication number05924653, 924653, US 4190345 A, US 4190345A, US-A-4190345, US4190345 A, US4190345A
InventorsAlfred S. Taylor
Original AssigneeScott Paper Company
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Lithographic plate processing apparatus
US 4190345 A
Abstract
Disclosed is an improved lithographic plate processing apparatus which comprises means for moving an exposed lithographic plate through the apparatus on an uphill slope, developer means within the apparatus for applying a developer liquid to the plate as it moves through the apparatus, and gumming means within the apparatus for applying gum to the plate after it has been developed, the gumming means including a baffle member under which the plate passes in contact and which forms a dam to hold a puddle of gum on the plate and against the baffle member, and spray means for spraying the gum onto the plate, the improvement comprising, as part of the gumming means, a rotatable gumming scrub brush between the baffle member and the spray means and in a position to scrub the plate when it passes thereunder.
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Claims(3)
What is claimed is:
1. In a lithographic plate processing apparatus which comprises means for moving an exposed lithographic plate through the apparatus on an uphill slope, developer means within the apparatus for applying a developer liquid to the plate as it moves through the apparatus, and gumming means within the apparatus for applying gum to the plate after it has been developed, the gumming means including a baffle member under which the plate passes in contact to enter the gumming means and which forms a dam to hold a puddle of gum on the plate and against the baffle member, and spray means for spraying the gum onto the plate at the downstream end of the gumming means whereby the gum flows downhill over the upwardly moving plate, the improvement comprising, as part of the gumming means, a rotatable gumming scrub brush between the baffle member and the spray means and in a position to scrub the plate when it passes thereunder after passing through the puddle of gum and before passing the spray means:
2. The lithographic plate processing apparatus of claim 1, wherein the gumming scrub brush rotates against the plate only in a direction against the movement of the plate.
3. The lithographic plate processing apparatus of claim 2, wherein the spray means also sprays gum onto the gumming scrub brush.
Description
TECHNICAL FIELD

The present invention is an improved lithographic plate processing apparatus of the type which automatically develops and gums an exposed lithographic printing plate.

BACKGROUND ART

In the lithographic printing process, a lithographic plate comprising an aluminum sheet is initially coated with a photosensitive layer. A negative is applied over the photosensitive layer and the two are exposed to high intensity light, the negative is then removed, and the plate is processed to develop it. Although some manual developing is still done, the large scale commercial use of lithographic plates has made automatic processing of necessity. Numerous apparatus have been proposed to perform such processes. In general, the more successful machines have emulated the normal development procedures by subjecting the plate to a scrubbing action while flooding the plate with developer liquid and then flooding the plate with gum arabic. However, there has always been need to improve the apparatus to perform tasks more satisfactorily.

DISCLOSURE OF THE INVENTION

It is an object of the invention to provide an improved lithographic plate processing apparatus.

This and other objects are provided by the present invention, which is an improvement in a lithographic plate processing apparatus which comprises means for moving an exposed lithographic plate through the apparatus on an uphill slope, developer means within the apparatus for applying a developer liquid to the plate as it moves through the apparatus, and gumming means within the apparatus for applying gum arabic or other plate finisher to the plate after it has been developed, the gumming means including a baffle member under which the plate passes in contact and which forms a dam to hold a puddle of gum on the plate and against the baffle member, and spray means for spraying the gum onto the plate. The improvement comprises, as part of the gumming means, a rotatable gumming scrub brush between the baffle member and the sprays means and in a position to scrub the plate when it passes thereunder.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawing is a cut-away side view of the apparatus of the present invention illustrated schematically.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to the drawing, the path of an exposed lithographic plate passing through the apparatus on a slight uphill slope is illustrated by the arrows. The plate is first gripped by a pair of rotating rubber covered feed rolls 1 and 2 and fed into the apparatus, where it slides over a support member 3 and under a flexible baffle member 4. Baffle member 4 acts as a seal to prevent developer fluid from draining back onto the pair of feed rolls 1 and 2.

Immediately beyond baffle member 4, the plate passes under a spray bar 5, extending across the width of the plate, which sprays developer liquid onto the exposed surface of the plate. The plate then passes under a small opening into an enclosure 6 where the plate is scrubbed by rotating brushes 7 and 8. The first brush 7 is a hard bristle brush and rotates in the direction of plate movement to provide adequate brushing pressure without catching the forward edge of the plate. The second brush 8 is a soft bristle brush and rotates against the travel of the plate to provide a final cleaning station beyond which the "dirty" developer is not allowed to flow. This brush 8 has a doctor blade 12 to prevent dirty developer from being thrown forward.

Above the plate and between brushes 7 and 8 is a second developer liquid spray bar 9 extending across the width of the plate and providing fresh developer. A drain 10 is located beneath the path of travel of the plate and between brushes 7 and 8. Dirty developer fluid passes through drain 10 and is recirculated through filters (not shown). After passing under brush 8, the plate slides along support member 11, passing through an opening in enclosure 6, and into the second pair of rotating rubber covered feed rolls 14 and 15. A disposable plush wiper member (not shown) is preferably positioned against feed roll 14 to maintain the roll in a clean condition. Just beyond the enclosure 6 is a spray nozzle 13 which applies a final applicaton of fresh developer liquid to clean the plate.

The second pair of feed rolls 14 and 15 feed the plate into the gumming section where it passes over a support plate 16 and beneath a flexible baffle member 17. The baffle member 17 forms a seal to prevent the gum from flowing from the gumming section of the apparatus back against the second pair of feed rolls 14 and 15 or into the developing section. It also forms a dam against which a puddle of gum 23 forms to assure overall coverage of the plate. Just beyond baffle member 17 the plate passes under a rotating nylon bristle brush roll which rotates in a direction against the movement of the plate.

The gum is applied by spray bar 19 extending across the width of the plate and spraying at the downstream end of the gumming section and onto the brush roll 18 to keep it wet with gum. The gum is sprayed on the downstream end of the gumming section to allow maximum contact time with the plate.

After gumming, the plate is fed into a third pair of rubber feed rolls 20 and 21 which push the plate from the apparatus. The apparatus includes an enclosure cover 22 to prevent loss of the developer liquid and gum arabic. A drying section may be added, if desired, to the end of the gumming section.

The feed rolls 1, 2, 14, 15, 20, and 21 and the developer scrub brushes 7 and 8, and the gumming brush 18 are all driven by either chain and sprocket or belt drive means (not shown). The pairs of feed rolls are spaced apart a distance less than the length of the plate so that one pair grips the plate before the preceding pair releases it. The uphill slope of the path of travel of the plate is preferably about 5.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3528358 *Apr 19, 1966Sep 15, 1970Ball CorpPrinting plate processing apparatus
US3589261 *Jan 16, 1968Jun 29, 1971Du PontPhotographic developing apparatus
US3621772 *Sep 4, 1969Nov 23, 1971Rogers CorpPlate processor
US3682079 *Apr 9, 1969Aug 8, 1972Casson Edward A JrAutomatic lithographic plate developing machine
US3694142 *Dec 21, 1970Sep 26, 1972Brueckner Apparatebau GmbhApparatus and methods for applying liquids to fabrics
US3719133 *Feb 18, 1972Mar 6, 1973Haracz ELithographic plate developing apparatus
US3732808 *Mar 18, 1971May 15, 1973Polychrome CorpApparatus for developing offset printing plates
US3903541 *Jul 27, 1971Sep 2, 1975Gaisser Jr Eugene JApparatus for processing printing plates precoated on one side only
US3906536 *Jul 27, 1971Sep 16, 1975Graham Robert CApparatus for processing printing plates precoated on both sides
US3916426 *Jul 1, 1974Oct 28, 1975Polychrome CorpApparatus for developing offset printing plates
US3936853 *Jun 6, 1974Feb 3, 1976Mart Milam EDeveloper apparatus for lithographic plate processing system
US3965343 *Mar 3, 1975Jun 22, 1976The United States Of America As Represented By The Secretary Of The NavyModular system for performing the discrete fourier transform via the chirp-Z transform
US3983758 *Nov 5, 1974Oct 5, 1976Buckler Industries, Inc.Automatic processor for offset plates
US4001854 *Jan 7, 1975Jan 4, 1977Vickers LimitedPlate processing machines
US4081815 *Dec 26, 1973Mar 28, 1978American Hoechst CorporationApparatus for guiding sheet material into counterrotating brushes
US4091404 *Jan 22, 1976May 23, 1978Hoechst AktiengesellschaftApparatus for developing photosensitive material
GB1381523A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4264180 *Oct 16, 1979Apr 28, 1981Hilton Richie CProcessing apparatus
US4740075 *Sep 17, 1987Apr 26, 1988Hoechst AktiengesellschaftDevice for processing photosensitive materials
US5839011 *Aug 13, 1997Nov 17, 1998Mitsubishi Paper Mills Ltd.Apparatus for processing photosensitive material
US7704679Nov 9, 2006Apr 27, 2010Agfa Graphics NvMethod of making a lithographic printing plate
US8092983Nov 9, 2006Jan 10, 2012Agfa Graphics NvMethod of making a lithographic printing plate
US8119330Nov 9, 2006Feb 21, 2012Agfa Graphics NvMethod of making a lithographic printing plate
US20080254391 *Nov 9, 2006Oct 16, 2008Agfa Graphics NvMethod of Making a Lithographic Printing Plate
US20080274427 *Nov 9, 2006Nov 6, 2008Agfa Graphics NvMethod of Making a Lithographic Printing Plate
US20080286695 *Nov 9, 2006Nov 20, 2008Agfa Graphics NvMethod of Making a Lithographic Printing Plate
US20120111266 *Oct 6, 2011May 10, 2012Seiji NogeProcessing apparatus for preparing lithographic printing plates
CN101322076BNov 9, 2006Mar 16, 2011爱克发印艺公司Method of making a lithographic printing plate
EP1788442A1 *Nov 18, 2005May 23, 2007Agfa Graphics N.V.Method of making a lithographic printing plate
EP1788443A1 *Nov 18, 2005May 23, 2007Agfa Graphics N.V.Method of making a lithographic printing plate
EP1788444A1 *Nov 18, 2005May 23, 2007Agfa Graphics N.V.Method of making a lithographic printing plate
EP2214056A3 *Nov 18, 2005Aug 11, 2010Agfa Graphics N.V.Method of making a lithographic printing plate
EP2772805A1 *Nov 18, 2005Sep 3, 2014Agfa Graphics NvMethod of making a lithographic printing plate
WO2007057336A1 *Nov 9, 2006May 24, 2007Agfa Graphics NvMethod of making a lithographic printing plate
WO2007057348A1 *Nov 9, 2006May 24, 2007Agfa Graphics NvMethod of making a lithographic printing plate
WO2007057349A1 *Nov 9, 2006May 24, 2007Agfa Graphics NvMethod of making a lithographic printing plate
Classifications
U.S. Classification396/606, 118/415, 396/627, 118/119
International ClassificationG03F7/30
Cooperative ClassificationG03F7/3042
European ClassificationG03F7/30E
Legal Events
DateCodeEventDescription
Oct 22, 1987ASAssignment
Owner name: S.D. WARREN COMPANY
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:SCOTT PAPER COMPANY;REEL/FRAME:004811/0245
Effective date: 19871013
Mar 17, 1995ASAssignment
Owner name: S.D. WARREN COMPANY, MASSACHUSETTS
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SCOTT PAPER COMPANY;SCOTT CONTINENTAL N.V.;REEL/FRAME:007381/0264
Effective date: 19941220
Mar 20, 1995ASAssignment
Owner name: CHEMICAL BANK, AGENT, NEW YORK
Free format text: SECURITY INTEREST;ASSIGNOR:S.D. WARREN COMPANY;REEL/FRAME:007388/0328
Effective date: 19941220